For the amount of time I spent attempting to get my Dad's old laptop working, it would have been cheaper for me to buy him a new laptop.
He bought it on a car-boot sale for £100. It was a Fujitsu Pentium 4 (yes, the desktop processor) running on a really obscure chipset with no up-to-date drivers. XP barely ran properly on it.
I eventually persuaded him to fork out for a new laptop, which I sourced for him. It's been a lot quieter on the support front since.
...except that because he insists on using Windows, and he clicks 'yes' on any prompt which pops up, the amount of crap installed on there after a month of me not clearing it out for him is unbelievable. He's installed programs which install other programs as part of their uninstall procedure! His windows explorer tool bar takes up half the screen with plug-ins he's inadvertently installed.
What can you do though when it's one of your parents...? :/